Normalization
transitive dependency
A condition in which an attribute is dependent on another attribute that is not part of the primary key.
prime attribute
A key attribute; that is, an attribute that is part of a key or is the whole key.
Denormalization
A process by which a table is changed from a higher-level normal form to a lower-level normal form, usually to increase processing speed. This potentially yields data anomalies.
Normalization
A process that assigns attributes to entities in such a way that data redundancies are reduced or eliminated.
atomicity (atomic transaction property)
A property of transactions that states that all parts of a transaction must be treated as a single logical unit of work in which all operations must be completed (committed) to produce a consistent database
dependency diagram
A representation of all data __________ (primary key, partial, or transitive) within a table.
2NF
A table in ______ may still contain transitive dependencies
Third Normal Form (3NF) - 2NF
A table is in _______ when it is in ____ and no nonkey attribute is functionally dependent on another nonkey attribute; that is, it cannot include transitive dependencies.
Fourth Normal Form (4NF) - 3NF
A table is in ________ if it is in ______ and contains no multiple independent sets of multivalued dependencies.
atomic attribute
An attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided into other name components
nonkey attribute
An attribute that is not part of a key
determinant
Any attribute in a specific row whose value directly determines other values in that row.
cannot
Choose - can or cannot? A table with a single-attribute primary key _______ exhibit partial dependencies
Boyce-Codd Normal Form (BCNF) - 3NF
Form where every determinant is a candidate key. A table that is in _______ must be in _______.
repeating group
In a relation, a characteristic describing a group of multiple entries of the same type that exist for a single key attribute occurrence. For example, a car can have multiple colors for its top, interior, bottom, trim, and so on.
partial dependency
In normalization, a condition in which an attribute is dependent on only a portion (subset) of the primary key.
Granularity
Refers to the level of detail represented by the values stored in a table's row. Data stored at their lowest level of granularity are said to be atomic data.
Second Normal Form (2NF) - 1NF
The _____ stage in the normalization process, in which a relation is in _____ and there are no partial dependencies (dependencies in only part of the primary key).
First Normal Form (1NF)
The ________ stage in the normalization process. It describes a relation depicted in tabular format, with no repeating groups and a primary key identified. All nonkey attributes in the relation are dependent on the primary key.
key attribute
The attribute(s) that form(s) a primary key.
join
The more tables you have the more ______ operations you need
True
True of False: A table that is not in 3NF may be split into new tables until all of the tables meet the 3NF requirements
True
True or False: A table in 3NF might contain multivalued dependencies that produce null values or redundant data
False
True or False: higher forms of normalization make the database speed faster
False, its 2NF
True/False: 1NF contains no partial dependencies
3NF
Which NF contains no transitive dependencies?
E
Which of the following are attributes of larger tables a) cumbersome indexing b) data redundancies c) data anomalies d) less efficient data updates e) all of the above
C
Which of the following can be in 1NF: a) partial dependency b) transitive dependency c) both a and b d) no primary key selected
primary key is based on only a single attribute
a 1NF table is automatically in 2NF when...
a table has only a single candidate key
a 3NF table is automatically BCNF when....
nonprime attribute
an attribute that is not part of a key. it cannot derive to prime attribute in BCNF
multivalued dependency
one key determines multiple values of 2 other attributes that are independent
3
the optimal database implementation requires that all tables be at least in ___NF?
d
which NF contains no multivalued dependencies? a) 1NF b) 2NF c) 3NF d) 4NF